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1999 Mazda Protege LX - P0705 Code: Is This Relevant to a Manual Transmission?

Model: 1999 Mazda Protege LX Fault Code: P0705 Posted: 2008-02-19 15:11

I recently purchased a 1999 Mazda Protege LX with poor credit, so I had little choice but to buy from an untrustworthy dealer. Within 30 days of purchase, they replaced the clutch — however, it was already damaged before I received the car, and they absorbed the cost. After returning the vehicle, the check engine light came on. I brought the car back today for a diagnostic, but the technician initially reported code P0705 and claimed he didn't know what it meant. He said it's a transmission-related error and that it only applies to automatic transmissions. Since my car has a manual transmission, he dismissed it as irrelevant. However, when I asked him to verify with another tool, they later stated the code was no longer present. My concern is significant: after the faulty clutch replacement, the vehicle redlined and stalled repeatedly. It would not rev below 6000 RPM — a clear sign of potential engine or transmission damage. I suspect the dealer may have simply reset the code to avoid further repair costs. I'm asking for clarity: What does P0705 actually mean? Is it applicable to manual transmissions like mine? The original diagnostic tool clearly showed P0705 — not P0704 (Clutch Switch Input Circuit Malfunction) — and I was present during the entire process. Had I not been there, I believe they would have simply reset the code. I'm seeking reliable information to determine whether this is a real fault or just a misdiagnosis that could lead to further damage if ignored.

Related fault codes
P0705
Comments (7)
Anonymous 2008-02-19 16:01

P0705 indicates a malfunction in the Transmission Range Sensor Circuit (PRNDL Input). Does your car currently run normally? If so, is it still under warranty or with the dealer? Regardless of their warranty terms, I strongly recommend taking it to a qualified mechanic — you might do a better job than they did.

Anonymous 2008-02-19 18:16

Double-check if the code was actually P0704. P0704 refers to Clutch Switch Input Circuit Malfunction and is more relevant to manual transmissions. I agree with the original poster — this issue should be addressed by a competent technician, not just reset.

Anonymous 2008-02-19 18:35

I would halt all payments until the problem is properly diagnosed and fixed. This could indicate deeper mechanical failure due to poor workmanship.

Anonymous 2008-02-20 15:36

The car was returned to me, but the check engine light came back on today. The dealer has asked me to return later in the week. My dad, a mechanic, and several friends who do auto work all believe this is likely a minor issue — but I don’t see it that way. If more damage occurs due to their negligence, I will keep returning for repairs until the warranty expires. After that, I plan to modify the car extensively — including engine, transmission, clutch, fuel pump, and adding a turbo. I’m now very concerned about what P0705 could indicate. After posting here, two friends called me back and confirmed it was P0705, not P0704. My dad also checked it and agrees with the diagnosis. I’ll keep you updated on how things progress. In the future, when I install an RX-7 engine, I’ll be able to test more issues and see what happens.

Anonymous 2008-02-20 16:58

It's possible the Powertrain Control Module (PCM) in your car is programmed for an automatic transmission. I’d recommend visiting the dealer directly or checking with a specialist who can confirm the PCM compatibility. If anyone has seen this code on a 1999 Mazda Protege with a manual transmission, their insight would be valuable.

Anonymous 2008-03-16 20:06

I had the same P0705 issue on my 2000 Mazda Protege. It turned out to be an unplugged connector in the manual transmission housing — located deep inside, just visible from above. After reconnecting it, the check engine light went off after two test drives. Another possibility is a faulty clutch switch; the ECU flags P0705 when it doesn’t detect clutch engagement or disengagement as expected. Interestingly, the previous owner took this car to multiple dealerships and independent shops — none of which found the issue. He ended up paying $500 for a new ECU, which I believe was unnecessary.

Anonymous 2008-07-05 07:52

Hi everyone, I also own a 1999 Mazda Protege (SE model, 1.6L engine, base version) and am experiencing P0705 as well. Like me, it's a manual transmission — so the initial diagnosis suggesting this code is irrelevant seems questionable. My OBD-II scanner shows the code points to an automatic transmission system, which raises concerns. I’m looking for the connector near the transmission shift housing — under the leatherette cover? I suspect a faulty clutch switch instead. Here’s what I’ve noticed: when hot and stuck in traffic (not on highways), if the gear stick is in neutral with the clutch not pressed, the engine idles around 2000 RPM. When I press down on the clutch, it drops to about 1000 RPM — and this increases over time as the car runs. When cold, idle RPM stays around 800 regardless of clutch position. This behavior has been present for about 1.5 months. The car was previously serviced at a garage for suspension work — I trust them, so I’m not blaming them yet. I recently bought an OBD-II scanner to better understand the MIL readings. I’ll check both the transmission connector and the clutch switch soon and report back as soon as possible. Thanks for the help! Pierre-Marc